Militants in the Gaza Strip pounded southern Israel with rocket fire today, killing three people as the Israeli military continued with a second day of intense air raids and naval attacks on militant targets.

With Israel threatening to invade the Palestinian territory, the heaviest fighting between Israel and Hamas in four years showed no signs
of letting up.

Thirteen Palestinians, including four civilians, have died since the fighting began yesterday when Israel assassinated Hamas' military chief, said Palestinian medical officials.

The clashes brought life to a standstill on both sides of the border.

Gaza's streets were mostly empty as the Israeli air force continued to strike targets. Residents across southern Israel remained huddled indoors or close to home, ordered by authorities to remain close to a network of public bomb
shelters.

The deaths in the southern Israeli town of Kiryat Malachi were the first in Israel since it launched its operation and raised the prospects of even fiercer Israeli retaliation.

Israeli leaders have said they are prepared to broaden the operation to a ground invasion if necessary, though there were no signs of extraordinary troop movements along the border.

"The military will continue acting to establish deterrence against Hamas and to return the calm," Defence Minister Ehud Barak said during a tour of southern Israel. He praised citizens for coping with the "tough moments to come".

Following the assassination of Hamas mastermind Ahmed Jabari, Israeli tanks, gunboats and aircraft struck dozens of sites across Gaza. More than 100 people have been wounded, say officials. Among the dead were two children.

Explosions rocked Gaza throughout the day today as well. Few in the territory's largest urban area, Gaza City, came out following the call for dawn prayers, and the only vehicles plying the streets were ambulances and media cars.

Most Gazans remained in
their homes, following developments on Hamas-run TV and local radio stations. Many also provided updates on their Facebook and Twitter accounts, providing news about airstrikes and rocket launches. Others shared prayers and called for militants to stand tough against Israel.

"My little four-year-old boy keeps asking me to pray with him every 10 minutes, saying, 'Mama. Let's pray together to Allah in order to be safe,"' one woman, Ghadeer Ahmad, wrote on her Facebook account.

While streets were quiet, bakeries and groceries remained open. No food shortages were reported, and electricity, which suffers frequent
cuts even during normal times, remained sporadic. Many families keep home generators to maintain power.

Thousands of people, including top Hamas officials, braved the threats to attend the funeral for Jabari, who had long topped Israel's most-wanted list for his role in deadly attacks and building up Hamas' formidable arsenal. Dozens of residents stood solemnly outside their homes or on their balconies as the procession walked by.

"We want to kill in the name of God," chanted mourners as angry gunmen fired automatic weapons into the air. Hundreds of people raised their index fingers in the air, chanting, "God is great."

"This crime will not weaken us. It will make us stronger and more
determined to continue the path of jihad and resistance," Hamas MP Mushir al-Masri said in a eulogy. "The enemy opened the battle and shall
bear the consequences."

Israel said Jabari's assassination was the start of a broader offensive, launched after days of rocket fire from the coastal territory. It was Israel's most intense attack on Gaza since a full-scale invasion four years ago, also in response to rocket fire.